source: buchla-68k/orig/MT/MTSTAT.C@ 6099cac

/*
   =============================================================================
        mtstat.c -- Multi-Tasker -- task status check
        Version 4 -- 1988-04-14 -- D.N. Lynx Crowe
        (c) Copyright 1988 -- D.N. Lynx Crowe
   =============================================================================
*/

#include "stddefs.h"
#include "biosdefs.h"
#include "mtdefs.h"

extern  short           setipl();       /* set processor IPL function */

extern  struct _mt_def  *_MT_;

/* 

*/

/*
   =============================================================================
        MTStat() -- check task status

                -3      stopped, waiting on a sempahore
                -2      stopped, not waiting
                -1      not found
                 0      running  (current task)
                 1      ready to run
                 2      waiting on a sempahore
   =============================================================================
*/

short
MTStat(tid)
unsigned tid;
{
        register TCB *tcp;
        register short oldipl, rv;

/* 

*/
        if ((struct _mt_def *)NIL EQ _MT_)
                _MT_ = (struct _nt_def *)XBIOS(X_MTDEFS);

        tcp = _MT_->mtp->TCBs;          /* point at start of  TCB list */
        rv = -1;                        /* preset return value */

        oldipl= setipl(7);              /* DISABLE INTERRUPTS */

        while (tcp) {                   /* check each TCB */

                if (tcp->flags & MTF_OCC) {             /* occupied ? */

                        if (tcp->tid NE tid)            /* continue if not tid */
                                goto nexttcb;

                        if (tcp->flags & MTF_RUN) {     /* running ? */

                                rv = 0;
                                break;
                        }

                        if (tcp->flags & MTF_RDY) {     /* ready to run ? */

                                rv = 1;
                                break;
                        }

                        if (tcp->flags & MTF_STP) {     /* to be stopped ? */

                                rv = -3;
                                break;
                        }

                        if (tcp->flags & MTF_SWT) {     /* waiting ? */

                                rv = 2;
                                break;
                        }

                        rv = -2;                        /* stopped */
                        break;
                }

nexttcb:
                tcp = tcp->fwd;                                 /* look at next TCB */
        }

        setipl(oldipl);                         /* RESTORE INTERRUPTS */

        return(rv);                             /* return status of task */
}